Communication system



April 12, 1938. v. M. BUGGE 2,113,611

COMMUNICATION SYSTEM Filed July 26, '1954 4 sheets-sheet 1 A TT IN V EN TOR.

April l2, 1938. v. M. BUGGE COMMUNICATIONSYSTEM 4 Sheets-Sheet 2 CODE POLAR ITY Filed July 26, 1954 LI NE T l2113422422322443814423141333144 .N E

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April 12, 193s. l

V. M. BUGGE COMMUNICATION SYSTEM 4 Smets-sheet :s

Filed July 26, 1934 EN TOR.; M.

April 12, 193s. v.' M BUGGE j, 2,113,611

COMMUNICATION SYSTEM Filed July 26, 1934 y Plas.

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4 Sheets-Sheet 4 Patented pr. 12, 1938 l 2,113,611 COMMUNICATION SYSTEM Vernon M. Bugge, Binghamton, N. Y., assignorto International Business Machines Corporation, New York, N. Y., a corporation of New York,

Application July 26, 1934, Serial No. 737,013

25 Claims.

longs and referred to as' the non-synchronousl system.

'I'he principle of the system of the present invention instead of depending on the synchronous operation of the transmitting and receiving units operates .on the basis of the transmission of signals of predetermined current values to which the receiving unit will give a definite and different response to each signal.

The system comprises in general a keyboard or typewriter similar to that of a conventional typewriter to originate impulses of predetermined current value by depression of the particular character key desired to be transmitted. Each character to be transmitted is represented by one or more impulses of diierent current strength and polarity, the particular signal for a selected character sent over the network When'the corresponding key is depressed releasing its pulse wheel or disc suitably provided to send the proper code. Each receiving station includes a galvanometer 4line relay and a line stepping relay, the former responsive to the definite current strength values and polarity of the impulses, whereas the latter is responsive only to the number of the impulses regardless of the impulse current strength and polarity. Y v

Due to the particular circuit arrangement em bodying the two types of relays just mentioned which are arranged to provide for'the conditioning of the proper circuit, the proper character is caused to be recorded at the receiving unit.

The invention as illustrated in its preferred form utilizes a power driven typewriter with mechansm of the type disclosed in the copending application Serial No. 677,018, filed June 22, 1933 by W. S. Lemmon. The present invention relates generally to printing telegraph systems, and it is v to be understood that the invention is not limited to the particular type of tele-typewriter shown in connection with the following disclosure but that it is also applicable to the conventional typewriter (Cl.- TIS-23) and teletype machines which are well known in the art.

It is therefore an object of this invention t0 provide a system whereby the selection of the predetermined characters depends solely on the 5 character impulse characteristics.

Another object of this invention is the provision for conditioning a group of circuits depending on the characteristics of the impulse transmitted and to energize one circuit of the up which is representative of the selected mi: ter. to be recorded.

Another object of this invention is the provision for energizing the selected circuit by a rticular characteristic of the selecting impulse.

Another object of this invention is the provision for restoring the conditioned circuits to normal condition after the selected character is recorded.

Further and other objects and advantages will be hereinafter set forth in the accompanying specication and claims, and shown in the drawings, which by way of illustration show what is now considered to be the preferred embodimentof the invention.

In the drawings:

Fig. 1 is a fragmentary, sectional elevation illustrating a portion of a power operated typewriter including a novel form of impulse transmitter.

Fig. 1--A is a fragmentary detail view illustrating the` impulse transmitter in operative pcsition.

Fig. 2 is a preferredform of code used in conjunction with the present invention.

Fig. 3 is a schematic circuit diagram of part of the system including a diagrammatic view of the stepping relay.

Fig. 4 is a similar diagram showing a system complete for the characters indicated in Fig. 2.

Fig. 5 is a schematic diagram showing the connections of the impulse transmitter.

Figs. 6 and 6--A illustrate a preferred form of the selection group relay.

Referring now to the drawings in which similar parts are designated bythe same numerals in the several views, it is believed that a clear understanding ofjthe invention will be had therefrom when considered in conjunction with the following description.

For the sake of clarifying the yfollowing description, the operation of the system will be given rst, followed by a detailed description of the parts vof the system necessary for a full understanding of this invention.

Operation It must be understood that the principle of the present system embodies the use of a code of different current values to obtain the desired 'selection of characters. Referring now to Fig. 2 a preferred form of code is shown for certain characters. Current strength of various values are used and are designated in the diagram as shown. The actual values of the current variations to be used depend on the transmission problem involved but for the purpose of description certain denite values will be assigned, as for example, current strength designated as 1 in Fig. 2 equal to 5 mils, 2 equal to 10 mils, 3 equal to 15 mils and 4 equal to 20 mils. 'Ihese numerals are associated with these definite current values to set forth the relationship of one to the other. The code for each separatecharacter also includes a denite polarity, some characters positive, others negative and a variance in the number of impulses, said impulses may be long or short, the reason for which will be explained hereinafter. It is important to note that the system to be disclosed employing a code similar to the one explained is not limited to the alphabetical and numerical characters but may be extended to any number desired. For this reason the system in its application .is not limited solely to printing telegraph' applications but may be applied to remote control of various machines such as the present day linotype machines, tabulating machines, etc.

Impulses according to the prearranged code set forth are transmitted by a suitable printer or typewriter when the selected depressed key, through a standard lever arrangement releases a cam corresponding to the selected key so as to engage the power driven roller to actuate the corresponding type bar, a further detailed explanation of which will be given hereinafter.

Simultaneously with the release of the said lever arrangement and engagement of the cam with said roller, the said cam engages a lever arrangement I0 and |08 (see Fig.'1) causing the lever I2 to release the extension I3 of pawl I8 mounted on pulse wheel or disc Il which is rotatably mounted on shaft I5vand driven by any suitable means. Disc Il is designed so that a plurality'of conducting members I6 consecutively engage brushes I1, so that during a single rotation the disc sends over the line via brushes |1 ,the number of characteristic impulses Vcorresponding to the prearranged code for the selected character. It is-to be understood that the cam II, lever arrangement I0 and |08 and disc I4 are provided for each character key, and that the corresponding current values selected may be supplied to brushes I1 and thence to the line or network, as shown in the schematic drawing in Fig. 5. It is to be noted that one of the conducting members I6 is longer than the other segments (Fig. 1), the reason for which will be explained later.

When lever I2 releasesextension I3 on pawl I8, pawl I8 through spring I3 engages clutch member 20 xedly mounted on shaft I5 so that- Referring now to Fig. 3, at the receiving station a galvanometer relay 2| of the well known Darsonval type and relay 22 are connected across the transmission network. The galvanometer relay 2| has eight contacts 23 .shown and are adapted to be engaged by armature 24, the particular contacts to be engaged by the said armature depending on the current strength and polarity of the Sgnal energizing coil 25 of said relay. Relay 2| is adjusted so as to be sensitive to the current strength and polarityof the impulses and not to the number of impulses transmitted. The short impulses energizing the relay coil 25 are not of sufficient duration to properly position or actuate the movable armature 24 to `the proper contacts 23 which are representative of the four diiferent current strength values used in the present embodiment of the system. However the long impulse which is the last impulse transmitted in the selected code is of suiiicient duration to cause the armature 24 to engage its proper contact 23 corresponding to the current value and polarity of the impulses transmitted. Therefore when and only when thev long impulse is transmitted representing the selected character is the relay 2| energized sufliciently to be properly positioned so that the armature 24 can supply current to the conditioned circuits, through the particular contact 23. Relay 22 connected to transmission'network is sensitive only to the number of impulses transmitted and closes its contact 26 for each impulse (short and long) to conduct current from the positive battery through lines 21, 28 and 29, contact 26, line 30, coil 3| of stepping relay generally designated at 32, normally closed 'contact 33A and line 3l to negative battery. For each impulse transmitted and causing the coil 3| of stepping. relay 32 to be energized, stepper contact arm 33 through lever arrangement 35 and ratchet 31 is stepped ahead so as to engage contacts 36 successively and corresponding to the number of impulses received.

Depending on the number of short and long impulses transmitted, the stepper contact arm 33 will be held in 'the constant engagement with its particular contact 36 so that the proper selection of the particular circuit may be made. The final position of contact arm 33 during the transmission of a signal is actually the summation of the number of independent impulses received. Contact arm 33 maintains the last position mentioned until the particular letter coil 38 -is selected and energized to record the character, which operation will be explained later.

Whenv the character is recorded relays 39 and III are energized to release the contact arm 33 and restore it to normal position as indicated in the figure. Energization of relay 39 attracts its armature 4I to cause its extension 42 to unlatch the ratchet wheel 31 and permit the restoration of arm 33 to normal position. At the same time relay 33 is energized, relay 40 is energized to open its contact 33A, in this manner preventing back circuits to be formed through contacts 36 when contact arm 33 is returned to normal position.

It was mentioned hereinbefore that the last impulse for each character is a long impulse, or where the character is represented by a single impulse, this impulse is always of long duration, so that it is seen that the stepper arm 33 is always engaging its corresponding contact 36 when the galvanometer relay 2| is energized to correctly position its armature 24. and for this reason the proper selection of the character letter coil 38 can be madey as follows.

Referring now to Figs. 3 and 4, the armature 24 of relayv 2| will engage one of the contacts 23 when its coil 25 is energized by the impulse of long duratio j the particular contact engaged depending on' the current strength 'value and polarity, as has been previously explained. Engagement of contact 23 by armature 24 allows current to be conducted through lines 21 and 28, contact 23, coil of relay 43 to negative side of line, energizing relay 43 to close its contact 44, whereupon current is conducted from the source through lines 21 and 45, contact 44, coil of relay 46 to the'negative side of the line, energizing relay 46 to close its contacts 41. The contacts 41 are arranged so that upon energization, the contacts 41a, 41h, 41e and 41d which are connected to the individual letter coil circuits close immediately to energize its respective coil, contact 41e is arranged to close a timed interval'later, this timed interval is equivalent to the time required to energize letter coils 38, when the contacts 41a, 41b, 41e and 41d are closed, suiiiciently to cause the character'to be recorded.

In practice this timed interval is equal to a fraction of a second so that special relay equipment is not'necessary to obtain this time delay. Contact 41e then closes when the energized letter coill 38 causes the character to be recorded, to conduct current from the source through lines 21 and 48, contact 41eline 49, lines 58 and 5|, coil of pawl release relay 39 and coil of step coil break relay 40, line 34 to other side of the line, energizing relays 39 and 40 restoring contact arm 33 to normal position, as previously ex plained.

A specific example will now be given, namely, for the character S. Referring to the code in Fig 2, itis seen that the signal consists of four..

impulses, three short and one long impulses of the first increment value and positive polarity. Depression of the character key S causes the release of pulse wheel or disc |4 for oneV revolution to transmit the signal over ,the network (Figs. 1 and 5). Line relay 22 is energized four times to close its contact 26 accordingly, energizing ,stepping relay 32 four times to position its contact arm 33 on its contact 4 (see Figs. 3

and 4'). 'I'he rst three impulses were of short duration and therefore were not sufficient to energize galvanometer relay 2| to position contact arm 24 on its proper contact. However the impulse of longer duration causes the arm 24 to engage contact I of relay 2| of the positive group of contacts, since the current strength is ofl the first increment value and positive polarity. Selector relay 43 is now energized, closing its contact 44 to energize selector group relay 46 and close its contacts 41a, 41h, 41e and 41d.

Contact arm 33 of relay 32 has been positioned to its contact 4, so that when contacts 41 close, a circuit is established through letter coil v38 representing S to be energized to cause a record to be made of the said' character. Immediately upon recording the character S contact 41e is closed to energize pawl release relay 38'and step coil break relay 40 causing the contact arm 33 to be reset to 'normal/position. It is necessary to time the operating parts of the above `circuits so asr to perform the describedoperatlons during the timed interval of the long pulse transmitted. It is seen'that the energized relays are restored to normal when the long impulse' iscompleted'.

A detailed description of the operating units embodied in the above described 'circuits will -now be given.

Selector group relay Referring now to Figs. 6 and G-A, a preferred form of the selector group relay 46 is shown. Mounted on base 52 which is fixed to side brackets 53 supporting insulated contacts 41a, 41h, 41e, 41d, and 41e, is the solenoid 54 with its plunger 55 plvotally connected with arm 56. Arm 56 is pivotally mounted on bracket 51 xedly supported by solenoid 56 and adapted to engage insulated contact springs 58 and 59. Anlinsulating member 68 is bridged across the top contact springs of the group 41a, 41h, 41e and 41d so that when arm 56 is rotated about its pivot 6| by the attracted plunger 55 all the contacts 41a, 41h, 41e and 41d are closed. Contact spring 58 is adapted to be engaged by arm 56 when it has been rotated sufficiently to close contacts 41a,

41h, 41e and 41d to the extentthat contact 41e is Referring now to Fig. 3, a preferred form of the stepping relay 32 embodied in the described system is shown and consists of contact arm 33 adapted to engage individual contacts 36 successively, and is fixed to ratchet wheel 31 rotatably mounted on shaft 62. 4llunger 63 of solenoid 3| is connected to link 64 one end of which is pivotally connected to arm 35. The tooth 65 projecting from arm is adapted to engage the teeth of ratchet Wheel 31 by virtue of spring 66, so that upon energization of solenoid 3| attractlng its plunger 63, arm 35 is moved'to the right to rotate ratchet 31 in a counterclockwise direction sufficiently to engage the next contact 36.

Pawl 42 of armature 41| holds the contact arm 33 ln its actuated position. Energization of pawl release'magnet 39 causes its attracted armature 4| to disengage pawl 42 from ratchet 31 to permit the spring 61 to return contact arm 33 to its normal position. f

Impulse transmitter Referring now to Figs. 1 and 5. As mentioned before for illustrative purposes, this invention isA shown as embodying a power driven typewriter of the type disclosed in the aforesaid copending Lemmon application, the construction of which is well known to those in the art, and hence requires only the following brief description. The illustrated machine is characterized by .the fact that the type bars do not have to be driven by yforce supplied by the operator, the keys being levers have tails 80 which extend downward in front of thevcontinuously rotating roller19. The tails 18 and 88 are bifurcated and embrace, respectively, pins 8| and 82 carried by bell cranks 83and 84. The bell cranks 83 and 84 are plv- The keys oted respectively at 85 and 86 upon other bell cranks 81 and 88. The bell cranks 81 and 88 are pivoted at 89 and 90 and carry at .the lower ends thereof, rotary cams 9| and' 92.

The bell crank 83 is provided at the lower end thereof with a lip 93 which normally stands in the position illustrated in Fig. 1, wherein it obstructs one of twopins 94 carried by the cam 9|, and thus prevents rotation of the cam. When a key lever 16 is depressed for rocking one of the tails 18 rearward, the associated bell crank 83 is rocked counterclockwise to move the lip 93 clear of the pin 94. The cam 9| stands in engagement with the roller 19 which is continuously rotated in a counterclockwise direction. As soon as the lip 93 is moved to a non-obstructing position, the roller 19 becomes effective to rotate the cam 9| through a half revolution. By .the time that the cam has turned through a half revolution the lip 93 has been returned to position to intercept theother pin 94 on the cam, and .to arrest rotation of the cam. The rotation of the cam, however, serves to rock the bellcranks 81 in a clockwise direction. The bell crank is thus caused to pull downward upon a link 95. 'Ihis rocks a further bell crank 96 in a clockwise direction, causing it to act through a link 91 to pull forward upon bell\crank 98 which is connected to the tail of type bar 13, and serves to operate the type bar. The motion of thebell crank 98 is controlled in part by a link 99 which is pivoted t beu crank 9s and to the frame 1|. A conholding disc I tractile spring |00 connected to the bell crank 98 tends to restore the parts tothe positions indicated in Fig. 1.

The tails which are carried by other key levers act in a similar manner to withdraw a lip |0I from obstructing relation to pins |02 provided on the cam 92. This results through the bell crank 88 and link |03 in the operation of the appropriate type bar inthe manner already described.

Attached to frame 1| is a further frame |04.'

Suitably mounted in frame |04 areshafts |05 and |06 upon which are rotatably mounted arms |01 and |08 respectively. At one end of arms I 01 and |08 are cam rollers |09 and III and at the other ends of said arms links ||0 and I0 are loosely connected thereto. The other end of link ||0 is connected to lever I2 which in its normalposition as shown in Fig. l engagesextension Il on pulse wheel or disc I4 to prevent rotation of said disc, which was explained hereinbefore. Pivotally mounted on lever I2 at I I4 is a pawl II2 which by virtue of spring I I3 urges said pawl in a clockwise direction to prevent disc I4 from moving in a coun rclockwise direction and aids in positively.A Brushes I1 are suitably mounted on the insulating block I I5 mountedon frame |04. Y I5 is obtained through the gearing IIB suitably connected to continuously rotating roller 19.

When a key lever 16 is depressed to release cam 9| as already described to enable said cam to be rotated a half revolution by roller 19 and thereby actuate the appropriate type bar 13, simultaneously during the rotation of cam 9| through a half revolution the said cam engages cam roller |09 on arm |01 to urge said arm far- 4ther away from the roller 19 (see Fig. l-A) and member 20 by virtue of spring I9, so that upon Power to rotate the shafts said engagement disc Il is rotated one revolution.

After lever I2 releases pawl I8 arm |01 returns to normal position as shown' in Fig. 1 and thereby positions lever I2 through link I|0 to obstruct further rotation of disc I4. Upon engagement of lever .I2 and extension I8 on pawl I8, pawl I8 is disconnected rfrom the rotating clutch member 20.

The transmitting and receiving printers may both be equipped with the impulse transmitter just described for transmission of messages in either direction. Since the printers may be used for either transmission or receiving of impulses the preferred form of actuating the key bars atI the receiving station will be explained in connection with the same printer illustrated. Since it is obvious that when the machine is equipped for both sending and receiving a disconnect switch may be provided in the circuit to brushes I1 so as to open the sending line when messages are to be received and to close it when messages are to be transmitted (see Fig. 5).

In Fig. 1 another frame |I8 is shownattached to frame 1I. Mounted on frame 8 is an insulating block II9 to which are secured solenoids 38. Plunger I2I of the solenoid is connected to link |22 plvotally mounted on post |23 supported by solenoid |20. Connected to the other end of link |22 is a rod |24 extending to key bar 16 and fastened thereto, so that upon energization` of solenoid 80, its attracted plunger |2| through link |22 and rod |24 cause key bar 18 to be depressed. Depression of said key bar causes its associated cam to be released and thereby cause the character to be recorded as explained hereinbefore. Where one wav communication is desired from one station to another, the transmitting station is equippedA with a printer unit and an impulse transmitter unit, at the receiving station the printer unit is equipped with the solenoids l0 connected in a manner just described.

While there has been 'shown and described and pointed out the fundamental novel features of `the invention as applied to a single modification. it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In a communication system comprising a plurality of circuits corresponding to predetervmined signals, means for transmitting signals consisting of code combinations of impulses of diiferent current strength and polarity, means responsive to said current strength and pol ty of the impulses and simultaneously responsive to the number of impulses to select circuits corresponding to the transmitted signals from the said plurality of circuits.

2. In a communication system comprising a plurality of circuits corresponding topredetermined signals, means for transmitting signals consisting of code combinations of impulses of diement current strength and polarity, means vresponsive to said current strength and polarity of the impulses and means simultaneously responsive to the number of impulses to select circuits corresponding to the transmitted signals from the said plurality of circuits, means to energize said selected circuits, and means to determine the timed interval the said circuits are perto the characteristics of said impulses, individual I mitted to remain energized.`

3. In a communication system comprising a plurality of circuits corresponding to predetermined signals, means for transmitting signals gized circuits, and means to deenergize the selectl ed circuits upon operation of said recording means. f

4. In a communication system, a character impulse transmitting unit comprising character keys, a power operated device and circuit control means controlled by the character keys and adapted to be operated by said vdevice to trans- 'mit character signals consisting of .code combina.-

tions of impulses of different current values, a selective relay having a plurality `oi" contacts corresponding to the number of current values used in the code, said relay responsive to said current values, a recording device, and means associated with said relay to controlselectively 4the operation of saidrecording device in accordance with the diierent current values transmitted.

5. In a communication systemv comprising a plurality of circuits corresponding "to predetermined signaIS, means for transmitting signals consisting of code combinations or impulses of diierent current strength and polarity, selective relaycontrol means responsive only to said current strength and polarity of the impulses and other relay means responsive only to the number of impulses to select circuits corresponding to the transmitted signals from the said plurality of pulse transmitting unit comprising character keys, a power operated device and circuit controlv means controlled by the character keys and adapted to be operated by said device to transmit character signals consisting of code combinations of impulses of different current strength and polarity, a character recording device including control means therefor, a plurality of circuits, each circuit including one of said device control means, a relay' device responsive to said current strength and polarity of the impulses and other relay means responsive to the number of impulses transmitted to select the circuits corresponding to the transmitted signals from the said plurality of circuits, and lmeans to operate the character recording device lcontrol means included in the said selected circuit.

7. In a communication system comprising a plurality, of circuits corresponding to predetermined signals, means forftransmitting signals consisting of code combinations of impulses of the said circuits are permitted to remain ener- 8. In a communication system, means for transmitting combinations of impulses of predetermined characteristics, relay means `responsive control circuits including control means associated with said relay means adapted to be selected in accordance with said impulse characteristics, a plurality of individual circuits controlled by each of said control means, and a main line relay means responsive to the number of impulses transmitted to control further selection of the circuits from the individual circuits selected by said control means.

9. In a communication system, means for transmitting signalsA consisting of impulses of diierent current values and polarity, a -relay responsive to said current strength and polarity of the impulses, control means associated with said relay andr adapted to be conditioned in accordance with each different current value and polarity transmitted, individual circuits controlled by each of said control means, and relay means responsive to each of said impulses transmitted to complete the selection of a single circuit from the said'individual circuits in accordance with the signals transmitted.

l0. The combination set forth in claim 8 including means to effect the lenergization of the individual circuits upon completion of the selection oi the said individual circuits.

11. The combination set forth in claim 9 including means to energize the single circuit for a particular timed interval upon completion of its selection.

12. In a communication system, means to transmit character impulses comprising a keyboard, 4power mechanism adapted to be tripped by each key; individual impulse distributing means to initiate a different number ofimpulses to represent various characters associated with the said power mechanism released to be eiective to initiate the said impulses when its corresponding power mechanism is tripped by the selected key.

13. In a communication system, means to transmit character signals, comprising a keyboard, a power mechanism adapted to be operated by each key, signal transmitting contacts,

and means associated with said contacts to control the, operation thereof, said means governed by the power mechanism operated by the selected key and including means to operate the diierent contacts `a dilerent number of times each time the corresponding mechanisms are operated by the keys.

14. In a communication system, means to transmit character signals comprising a keykeys, power mechanism adapted to be operated by each key, `individual control means associated with the said power mechanism and operated thereby, normally inoperative individual signal transmitting means, and means operated by said control means to render one of the said signall transmitting means operative a predetermined number of times in accordance with the code upon the operation of a selected key.

16. In a communication system/comprising a plurality/of circuits corresponding to predetermined signals, means for transmitting signals consisting of code combinations of impulses of different current strengths and polarity, means responsive. to said current strengths and polarity of the impulses and simultaneously responsive to the number of impulses to select particular circuits corresponding to the transmitted signals from the said plurality of circuits, a source of power supply, and means to maintain the power supply disconnected from the said circuits until the completion of the said selection of the particular circuits.

17. In a communication system, means to transmit character signals comprising code combinations of impulses of different current l strengths and polarity, a plurality of circuits, means responsive to the number of impulses included in said code to obtain step by step selection of certain groups of circuits from said plurality ofv circuits and means responsive to the .different current strengths and polarity of the impulses to complete a further selection of the circuits from one'of said groups of circuits.

18. 'I'he invention set forth in claim 1'7 in which the means responsive to the said numberof impulses is a stepping relay adapted to maintain the selection of said certain groups of circuits complet-e a further selection of particular circuits from one'of said groups of circuits, and recording means controlled and operated by said selected particular circuits.

20. In a communication system, means to transmit character Signals comprising code combinations of impulses of diil'erent current strengths and polarity, a plurality of circuits, relay meansresponsive to the number of impulses vincluded in said code to be operated step by step l from an initial position to obtain selection of certain groups of circuits from said plurality of circuits, means' included in said relay to maintain each selection of the said certain groups of circuits until the subsequent impulse in said code operates the said relay means to select a diierent group of circuits, means responsive to the diilerent current strengths and polarity of the impulses to complete a further selection of the circuit from one of said groups of circuits and means to return said relay means to said initial position upon completion of said selection.

21. In a communication system, means to transmit code combinations of impulses representing characters and to record said characters to be transmitted, said means comprising a plurality of character recording instrumentalities, power operating devices individual to said instrumentalities, a keyboard comprising a multiplicity of keys each adapted to trip one of said vpower operating devices and operating a corresponding recording instrumentality, impulse distributing means associated with said power operating devices and adapted to be operated to transmit a code combination of impulses representing a character upon operation of a lselected key and said power operating device, and means whereby said power operating device is eilective -at the same time to operate the corresponding instrumentality to record the selected character.

, 22. vIn a communication system means to transmit code combinations of impulses representing characters and to record said characters to be transmitted, said means comprising a plurality of character recording instrumentalities, a constantly rotating power member, a multiplicity of character keys, individual devices operated by said power member upon depression of the corresponding keys to operate a recording instrumentality, impulse distributing means comprising a rotatable means and operated by said power member, individual distributor units for each character having a plurality of conducting segments thereon and adapted to be rotated by said rotatable means, means normally tending to prevent the rotation of said units and means operated by said devices to release the said units upon opnals toa transmission circuit, selecting a certain number of circuits. from a' p1urality in accordance with the current values and polarity of the signals, and selecting a single circuit from the selected number of circuits in accordance with the number of impulses of the signals, thereby operating `an indicating device in accordance with the character signals.

24. The method of signalling which comprises initiating character signals consisting of code combinations of impulses of different current values and polarity, applying the character signals to a transmission circuit, selecting a certain number of circuits from a plurality in accordance with the current values and polarity of the signals, selecting a single circuit from the selected number of circuits in accordance with the number of impulses of the signals, energizing the selected circuits and maintaining the selected circuits energized for a predetermined time interval.

25. The method of signalling which comprises initiating character signals consisting of code combinations oi' impulses of diii'erent current values and polarity, applying the character signals to a transmission circuit, selecting a certain number of circuits from a plurality in accordance with the current values and polarity 'of the signals, selecting a single circuit from the selected number of circuits in accordance with the number of impulses of the signals, energizing the selected circuits and controlling the operation of an indicator thereby and deenergizlng the selected circuits upon operation of the indicator.

vERNoN n. BUGG 

